I don't think PHP has anything to do with that. Probably more experienced coders (i.e. older, hence PHP), just cranking out great code. Language/stack has nothing to do with it.
For example, my day job I work with Android all day long. But as a side project, I wanted to make a small mobile game as a invitation for my wedding. So I loaded up Phaser.io and wrote some really easy Javascript. I had a working, playable game that night. To be fair, it's a really great framework. But I think choosing a framework that fits your needs at hand is much more crucial than which language or database you use.
For example, my day job I work with Android all day long. But as a side project, I wanted to make a small mobile game as a invitation for my wedding. So I loaded up Phaser.io and wrote some really easy Javascript. I had a working, playable game that night. To be fair, it's a really great framework. But I think choosing a framework that fits your needs at hand is much more crucial than which language or database you use.